On-line services are often used to store, organize, and share photos. In many contexts, such services have largely supplanted the use of paper photos and albums. Many types of on-line services offer photo management capabilities. For example, some web sites (e.g., Flickr) are geared toward photography enthusiasts. Other web sites (e.g., Facebook) are geared toward broader social networking applications, but do offer photo storage and management as one of their services.
In general, people may be interested in seeing photos of those who are in their true social network. Social networking sites allow people to declare who their “friends” are, and it might appear that a person's social network could be inferred by reading that person's list of “friends.” However, the concept of a “friend” in a social networking site is often over-inclusive. People tend to list not only their true friends, but also their co-workers, distant relatives, etc. People may have varying degrees of interest in seeing photos of the people they list as friends.
In an effort to identify a person's social circle, some services might draw inferences from information related to e-mail. For example, it might be inferred that a given person is friends with someone who appears in his contacts list, or with whom that person corresponds frequently by e-mail. However, some e-mails are sent for social reasons, otherso for business reasons. Many of the people who appear in a given contacts list might be business acquaintances, and a person might more interested in seeing photos of his or her friends than of his or her business acquaintances. Thus, selecting photos to show to a user based on whom the user frequently e-mails may result in a selection of photos that is uninteresting to the user.